The present invention is directed to the handling of one or more streams of documents and, more particularly, is directed to the high-throughput staging of documents and right-angle turning of document streams.
Staging devices are utilized in a wide variety of document handling and mail processing operations. Such operations can involve a number of different modules or stations that perform specific tasks, such as accumulating, folding, printing, shearing, merging, envelope stuffing, and combinations thereof. These operations often require that sheets be physically turned 90 degrees at some point on the sheet path, yet still demand that a commercially acceptable level of throughput be maintained. Examples of systems in which sheets must be physically turned in order to effect a change in conveying direction are disclosed in U.S. Pat. Nos. 5,362,039 and 5,439,208.
In some of these operations, two or more sheet streams must be merged into a single stream. One example is the processing of two-up material, which can typically be provided on a 17 inch continuous roll. The width of the roll is such that two 8.5xc3x9711 inch printed pages are disposed in adjacent relation to each other. Several side-by-side pairs of such pages are contained in succession along the length of the roll.
A staging module is typically used whenever an application requires that one or more sheets in one or more process streams be paused or held for a certain period of time while other operations are performed, initialized, or reset. In operations such as those briefly described above, the use of a staging module can be useful for assisting in the synchronization of the various operations being conducted on the sheets. Unfortunately, a conventional staging module can slow down throughput to an unacceptable level. This is because a sheet residing in a conventional staging module must completely exit the staging area before the next sheet in the sheet stream can enter therein. As a result, some document handling systems that could benefit from the use of a staging module avoid such use altogether. Throughput is further slowed in conventional operations that require sheets to be physically rotated at some point along the process path.
It would therefore be advantageous to provide a sheet stager apparatus that is capable of permitting a high level of throughput and is consequently useful in a wide variety of document handling and mail processing operations without impeding such operations. It would be further advantageous to provide a high-throughput stager apparatus that has the additional ability of turning the sheet path 90 degrees without requiring sheets to be physically turned, thereby eliminating the need for a separate conventional sheet turning module.
The present invention provides a right-angle sheet stager apparatus for merging multiple input sheet streams into a single output sheet stream. In one embodiment according to the present invention, the stager apparatus comprises a plurality of input channels. Each input channel includes a transport surface and a staging surface. Each staging surface is disposed downstream of its corresponding transport surface. One of the staging surfaces is disposed at an elevation different from an elevation of one of the other staging surfaces. An output channel includes an output surface. The output channel is oriented in a right-angle relation with respect to the input channels and communicates with the input channels at a merger location.
In another embodiment according to the present invention, a right-angle sheet stager apparatus comprises a plurality of input channels. Each input channel includes a transport surface, a staging surface, and a transitional member interposed between the transport surface and the staging surface. Each staging surface is disposed downstream of its corresponding transport surface. One of the transitional members includes an upper surface disposed at an elevation greater than an elevation of its corresponding staging surface. An output channel includes an output surface. The output channel is oriented in a right-angle relation with respect to the input channels and communicates with the input channels at a merger location.
In yet another embodiment according to the present invention, a right-angle sheet stager apparatus comprises an inside input path including an inside transport surface and an inside staging surface. The inside staging surface has an elevation and communicates with the inside transport surface at an inside interface location. The inside interface location includes an upper surface having an elevation greater than the elevation of the inside staging surface. An outside input path includes an outside transport surface and an outside staging surface communicating with the outside transport surface at an outside interface location. The outside staging surface has an elevation different from the elevation of the inside staging surface. The outside interface location includes an upper surface having an elevation greater than the elevation of the outside staging surface. An output path includes an output surface. The output path is oriented in a right-angle relation with respect to the inside and outside input paths, and communicates with the inside and outside input paths at a merger location.
In a further embodiment according to the present invention, a document handling apparatus comprises an input path structure, an output path structure, and a staging and document turning assembly. The input path structure includes an input surface and a first document moving device disposed in operative engagement with the input surface. The output path structure is oriented perpendicularly with respect to the input path structure and includes an output surface. The staging and document turning assembly is interposed between the input path structure and the output path structure and includes a staging surface and a second document moving device. The staging surface defines an interface between the input surface and the output surface. The second document moving device is disposed in operative engagement with the staging surface and is oriented perpendicularly with respect to the first document moving device.
The present invention also provides a method for merging multiple input sheet streams into a single output sheet stream oriented at a right angle with respect to the input sheet streams. The method comprises the following steps. A staging area is provided and includes a plurality of staging surfaces disposed at different elevations. A plurality of sheets are fed in a plurality of input sheet streams into the staging area, wherein each input sheet stream communicates with a corresponding one of the staging surfaces. A sheet outfeed area is provided and includes an output surface in communication with each of the staging surfaces. A first sheet is staged on a first one of the staging surfaces. The first sheet is brought into contact with a sheet driving mechanism. The sheet driving mechanism is activated to transport the first sheet towards the outfeed area. A second sheet is permitted to enter the first staging surface and to overlap with the first sheet prior to transportation of the entire first sheet out of the staging area. The method can further comprise the step of permitting a plurality of sheets to enter the first staging surface and accumulate thereon prior to transportation of the first sheet out of the staging area.
In another method for merging multiple input sheet streams into a single output sheet stream oriented at a right angle with respect to the input sheet streams, a staging area includes a plurality of staging surfaces disposed at different elevations and each staging surface includes a sheet driving element operatively associated therewith. A plurality of sheets are fed in a plurality of input sheet streams into the staging area. Each input sheet stream communicates with a corresponding one of the staging surfaces. A sheet outfeed area is provided, and includes an output surface in communication with each of the staging surfaces. A first sheet is staged on a first one of the staging surfaces, and a second sheet is staged on a second one of the staging surfaces. The first sheet is brought into contact with the sheet driving element of the first staging surface, and the second sheet is brought into contact with the sheet driving element of the second staging surface. The sheet driving element of the first staging surface is activated to transport the first sheet towards the outfeed area in a direction substantially perpendicular to at least one of the input sheet streams. The sheet driving element of the second staging surface is also activated to transport the second sheet towards the outfeed area in a direction substantially perpendicular to at least one of the input sheet streams. The first and second sheets are then merged into a single output stream substantially perpendicular to at least one of the input sheet streams.
The method can further comprise the step of causing a subsequent sheet to enter the first staging surface and to overlap with the first sheet prior to transportation of the first sheet out of the staging surface. The method can also comprise the step of permitting a plurality of sheets to enter the first staging surface and accumulate thereon prior to transportation of the first sheet out of the staging area.
The method can still further comprise the step of causing sheets from one or more of the input sheet streams to overlap at merger location.
Accordingly, it is an object of the present invention to provide a right-angle sheet stager apparatus that is capable of achieving higher levels of throughput than conventional staging devices.
It is another object of the present invention to provide a sheet stager apparatus in which sheets are permitted to overlap in the staging area and thereby increase throughput.
It is a further object of the present invention to provide a sheet stager apparatus in which tight control over the flow of the sheet streams is maintained even at the higher level of throughput achieved by the stager apparatus.
It is yet another object of the present invention to provide a high-throughput stager apparatus which also functions to turn the direction of the sheet stream path 90 degrees without causing the individual sheets to be physically rotated.
Some of the objects of the invention having been stated hereinabove, and which are achieved in whole or in part by the present invention, other objects will become evident as the description proceeds when taken in connection with the accompanying drawings as best described hereinbelow.